Radially expandable anchorage guide for trocars

ABSTRACT

An anchor guide for a trocar comprising a tubular body, formed by a plurality of substantially circular sectors, moveable radially toward and away from a longitudinal axis of the tubular body between a first position where they flank one another, according to a first substantially circular arrangement with diameter generally equal to that of the tubular body, and a second position at which they are generally equidistant from one another, according to a second substantially circular arrangement of greater diameter than that of the first arrangement. Each sector is rotatably connected to a support element and a manual operation is provided, moveably connected to the support element, for moving the sectors from the first to the second position and vice versa.

FIELD OF THE INVENTION

The present invention regards in general the field of equipment forlaparoscopic surgery and more in particular refers to a radiallyexpandable anchorage guide for trocars.

BACKGROUND ART

As is known, in the laparoscopic surgery field wide use is made ofinstruments called trocars which generate and maintain the accesschannels for the various surgical instruments used in operations.Schematically, a commercial trocar comprises a cannula and a valve bodysituated at one of its ends. Typically, the cannula has a diameter of 5or 12 mm with a length of 110-120 mm.

At the beginning of the operation, some holes are made, for example, inthe abdomen of the patient by using as many trocars equipped with anaccessory capable of penetrating the various tissue layers.Subsequently, such accessory is extracted and an inert gas isinsufflated in the abdomen through one of the trocars so as to generatethe necessary operating space.

The pressure generated inside the abdomen tends to push the trocarsoutwardly, so that various methods have been devised for theiranchorage. The most widespread solution foresees the use of a tube withinner diameter equal to the outer diameter of the trocar cannula andwith an outer threaded surface such to permit the surgeon to “screw it”into the access hole. The tube is then fixed to the cannula of thetrocar by means of elastic bands or friction systems.

During the operation, all of the necessary instruments are insertedthrough the trocars. In the case in which internal parts must beremoved, for example gall bladder, intestine parts, tumoral masses etc.,it may become necessary to carry out further access cuts of sufficientsize for the passage of the part to be removed. This need involvesmaking additional wounds of greater size than those left by the trocars,as well as the possibility of contamination through the walls of the cutduring the extraction step of the parts to be removed; all of thisresults in a more difficult patient recovery after the operation. Afterthe extraction, it is often necessary to continue to operatelaparoscopically and the additional cut compromises the gas seal so thatit is necessary to use instruments capable of restoring the seal.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an anchorage guide fora trocar which, taking advantage of the elasticity of the relaxedtissues (since they are anesthetized), can expand to generate thenecessary space for the extraction of the parts to be removed withoutthe need to carry out additional cuts.

Another object of the present invention is to provide an anchorage guidefor trocars of the type mentioned above on which it is possible to mountan autonomous valve system through which instruments or an adaptor forcommercial trocars can pass, if, after the extraction of the diseasedparts, it would be necessary to newly pressurize the abdomen and restartthe operation.

These objects are achieved with the anchorage guide for a trocaraccording to the present invention comprising a tubular body, formed bya plurality of substantially circular sectors, radially moveable fromand towards the longitudinal axis of the tubular body between a firstposition wherein they flank each other according to a firstsubstantially circular arrangement with diameter equal to that of saidtubular body, and a second position wherein they are equally spaced fromeach other according to a second substantially circular arrangement ofgreater diameter than that of the first arrangement. Each of the sectorsis rotatably connected to a support element and manual operation meansare foreseen, moveably connected to said support element, for moving thesectors from the first to the second position and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics, as well as the advantages, of the anchorage guidefor a trocar according to the present invention will be clearer from thefollowing description of an exemplifying and not limiting embodimentwith reference to the attached drawings wherein:

FIG. 1 is a perspective view of the anchorage guide according to theinvention in its closed position;

FIG. 2 is a perspective view of the anchorage guide in its openposition;

FIG. 3 is a cross sectional view of the anchorage guide of FIG. 1;

FIG. 4 is an exploded view of the anchorage guide according to theinvention;

FIG. 5 is a perspective view of the anchorage guide according to theinvention in a completely open position and with a diaphragm valveinserted therein;

FIG. 6 is a longitudinal sectional view of the anchorage guide of FIG.5;

FIG. 7 is a longitudinal sectional view of the anchorage guide accordingto the invention in its closed position with a commercial valve system;

FIG. 8 is a perspective view of the anchorage guide according to theinvention in is its closed position, equipped with a diaphragm valvewith a commercial trocar housed therein;

FIG. 9 shows a perspective view of the anchorage guide according to theinvention with a protective tube.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIGS. 1-4, a tubular body, generically indicated with1, is formed by three sectors 1 a of angular width equal to 120°. Fromone end of each of the sectors 1 a, a curved arm 2 extends in asubstantially tangential manner; the free end of the curved arm 2 isrotatably engaged with a pin 3. The three pins are in turn engaged inthree equidistant holes 5 formed on a first ring nut 4, called fixedring nut, orthogonal to the longitudinal axis of the tubular body 1 andin circumferential slots 6 made along a second ring nut 7, calledmoveable ring nut, coaxially arranged on the fixed ring nut 4. Thethreaded ends of the pins 3 projecting from the slots 6 of the moveablering nut 7 are finally engaged in respective threaded knobs 8, abuttingagainst moveable ring nut 7 opposedly with respect to the fixed ring nut4, thereby obtaining the mutual fixing of the various components.

The three sectors 1 a of the tubular body 1 form a channel of innerdiameter less than or equal to the outer diameter of the cannula of thecommercial trocar to be used, while the outer surface of the sectors 1 ahas a saw tooth thread, as in the anchorage cannulae of known type,capable of grasping the walls of the body cavity access hole.

The three curved arms 2 are housed within the fixed ring nut 4, coplanarthereto, and may be simultaneously rotated around the respective pins 3,to transmit an angular movement to the moveable ring nut 7. Followingthe rotation of the arms 2, the cylindrical sectors 1 a extendingtherefrom progressively divaricate from each other, passing from theclosed configuration illustrated in FIG. 1 to the open configuration ofFIG. 2.

Three angularly equidistant closure pins 9 and three thrust pins 10extend orthogonally from the face of the moveable ring nut 7 turnedtowards the fixed ring nut 4. When the tubular body 1 is in its closedposition, as shown in FIG. 1, the closure pins 9 abut on the convex sideof the respective curved arms 2 and maintain the three cylindricalsectors 1 a adjacent to each other, tightening them on the cannula ofthe trocar so as to permit the axial locking of the trocar. Inparticular, as shown in FIG. 4, the arms 2 have seats 2 a, within whichthe closure pins 9 are engaged. On the other hand, when the moveablering nut 7 is rotated in the direction of the arrow F of FIG. 3, thethrust pins 10 come into contact with the concave profile of the arms 2of the sectors 1 a and, sliding along them away from the hinge pins 3,ensure that the arms progressively extend. The opening of the sectors 1a first occurs quickly and then slows approaching the end stop; in thisway it is possible to exert a force as constant as possible throughoutthe opening step, since the resistance of the tissues increases as thedivarication of the sectors 1 a increases. At the stop end, the tubularbody 1 remains stably open when the thrust pins reach the dead point. Ifit is necessary to stop the opening in an intermediate position, it issufficient to tighten at least one of the three threaded knobs 8.

To ensure an adequate sealing of the gas on the patient side, a membrane11 is foreseen as shown in FIG. 4 and FIG. 7, while on the surgeon'sside the seal is ensured by a valve system such as that shown in FIGS. 5and 7. The membrane 11 has a variable thickness, and in particular incorrespondence with its minimum and maximum diameter terminates withrespective toroidal rings 11 a and 11 b. The maximum diameter ring 11 bis inserted in a perimetrical groove 4 a of the ring nut 4, as isvisible in FIG. 6, while the minimum diameter ring 11 a is tight at thebase of the sectors 1 a. No groove for housing the ring 11 a is foreseenon said sectors, since the correct position is maintained both becauseit is a rest position and because the membrane is forced by the abdomenof the patient against the ring nut 4.

The radially expandable anchorage guide for trocars according to thepresent invention is used in the following manner. At the beginning ofthe operation, during the insertion step of the trocar in the abdomen(for example), the anchorage guide according to the present invention isused as if it was a normal anchorage tube of the trocar to the abdominalwall. As shown in FIG. 8, the three sectors 1 a are closed around thecannula 12 of the trocar and are tightened to it by rotating themoveable ring nut 7 with respect to the fixed ring nut 4, and tighteningat least one of the locking knobs 8. In the particular case wherein thetrocar inserted is calibrated on the inner size of the closed tubularbody 1, tightening the locking knob 8 can be avoided since the system isirreversible when in completely closed position. A valve 13, of the typeillustrated in FIGS. 5 and 6, is closed around the trocar tube to ensurea perfect gas seal. In the case in which the valve is that illustratedin said figures, it is not necessary to tighten the tubular body 1 onthe cannula 12 of the trocar, since the same valve can ensure the axialanchorage of the trocar. Indeed, when the membrane tightens around thecannula of the trocar, it generates a consistent radial force which, dueto the high coefficient of friction between the same membrane and thecannula of the trocar, ensures a strong axial seal.

If during the operation it becomes necessary to insert a trocar ofgreater size, it will suffice to open the valve 13 of FIG. 8, open thetubular body 1 by unlocking the cannula 12 of the trocar, extract thetrocar to be substituted, insert the new trocar and tighten the tubularbody 1 and the seal valve 13 on it.

If during the operation it becomes necessary to remove an internal mass,the tubular body 1 may be divaricated to its maximum expansion so that,once the trocar and the seal valve is removed, an access channel isgenerated at the abdomen of sufficient dimensions for the passage of themass to be removed.

To protect the walls of the access hole from possible contaminations(for example during the extraction of a tumoral mass in the absence ofother types of protection), it is possible to insert within thedivaricated sectors 1 a a tube 14 (see FIG. 9) after having overturnedthe elastic membrane 14 a inside the tube itself. In particular, thetube 14 is composed of a rigid cylinder of thin thickness buried withinan elastic membrane terminating at both ends with two large diameterdiscs with reinforced edges, one of which is the membrane 14 a. For itsinsertion inside the divaricated tubular body 1, the inner disc ormembrane 14 a is folded inside the tube 14 and subsequently made toexpand inside the abdomen. The membrane 14 a protects fromcontaminations the inner wall of the abdomen near the access hole. Theaxial position of the tube 14 is ensured by the tightening of the threesectors 1 a on it. The tube 14 has an outer elastic disc 15 at the otherend which may be folded on the moveable ring nut 7 of the anchorageguide so as to protect it from contamination. FIG. 9 has the expandableanchorage guide according to the invention in a configuration suitablefor the extraction of an internal mass. To extract the tube 14, itsuffices to further divaricate the sectors 1 a and pull the tube 14through the outer disc 15.

The valve 13 illustrated in FIGS. 5 and 6 is based on the principal ofoperation of a commercial device named “LAP-DISC”, described in the U.S.Pat. Nos. 6,110,154 and 6,589,167 and used for making an abdomen accessfor the surgeon's hand in hand-assisted laparoscopic surgery operations,even if it uses a different method for maintaining the set position.

With particular reference to FIGS. 5 and 6, the valve 13 comprises afixed support 16 which can be connected by bayonet coupling to the outerface of the moveable ring nut 7. On the latter, in fact, radialexpansions 17 are foreseen defining circumferential grooves 18 with theouter face of the moveable ring nut 7, within which radial tongues 19are friction engaged, extending from the outer wall of the fixed support16. The seal between the fixed support 16 and the moveable ring nut 7 isensured by a seal ring 20 arranged therebetween. The valve 13 moreovercomprises a control ring nut 21 rotatably engaged within the fixedsupport 16 and maintained in the desired angular position by means offlexible arms 22 axially extending from the fixed support 16. The arms22 have inner radial projections 23 which are engaged in axial grooves24 formed on the outer surface of the control ring nut 21.

The obturator of the valve 13 comprises an elastic membrane 25 having inrest position a toroidal shape with “omega” cross section, which ismaintained tight on the inner walls of the control ring nut 21 and thefixed support 16, respectively, by means of expansion rings 26 and 27 ofrectangular section, cut sideways to permit the flattening of themembrane against the walls of the control ring nut 21 and the fixedsupport 16 without gap.

Rotating the control ring nut 21 with respect to the support 16, theflexible arms 22 bend, making the projections 23 move from one groove 24to the other, so that the elastic membrane 25, due to the torsion towhich it is subjected, closes radially like a diaphragm. With anappropriate rotation angle of the control ring nut 21, it is possible tocompletely occlude the opening of the valve 13, or partially occlude itin case the cannula of a trocar must pass through said opening,tightening the membrane 25 around it and ensuring the gas seal and aconsistent axial tightening.

The expandable anchorage guide according to the invention, in additionto having the diaphragm valve described above, may naturally be employedeven in association with valves for trocars of another type, such asthat illustrated in FIG. 7.

The valve herein illustrated is of double seal type: i.e. it has a firstelastic obturator 26 with flute mouth geometry which in rest ismaintained in closed position by the pressure established in the bodycavity. If an instrument is inserted, the flute mouth 26 obturator opensin correspondence with the longitudinal cuts, losing however the gasseal. A second obturator 27 is therefore foreseen, upstream of the firstand formed by an elastic membrane with calibrated hole to make a seal ona particular instrument diameter. Normally, having to insert aninstrument with different diameter, the second obturator block 27 fixedwith bayonet coupling to the first obturator must be substituted. Thedouble obturator scheme as illustrated allows instruments to beextracted and inserted without losing the seal, while, when theinstrument is inserted, the second obturator ensures the seal by forcingradially against the instrument. The valve system described andillustrated in FIG. 7 is among the most commercially widespread, butthere exist many others predominantly intended to house instruments withdifferent diameters, without the need to interchange the secondobturator. The instrument according to the invention may house, by meansof an appropriate adaptor, any commercial sealing system.

Naturally, the tubular body 1 of the expandable anchorage guideaccording to the invention can be made in a different number ofcylindrical sectors 1 a with respect to that described and illustrated.In this manner, it is possible to better approximate the circular shapeof the realized opening, through the cost of the instrument increases.

Variations and/or modifications can be made to the anchorage guide fortrocars according to the present invention without departing from theprotective scope of the invention as set forth in the following claims.

1. An anchor guide for a trocar for use in laparoscopic surgery, theguide comprising a tubular body with a member for its anchorage to anaccess hole for entering a body cavity, wherein the tubular body isformed by a plurality of substantially circular sectors, moveableradially toward and away from a longitudinal axis of the body between afirst position, where they flank one another according to asubstantially circular first arrangement of diameter generally equal tothat of the tubular body, and a second position, at which they aregenerally equidistant from one another according to a substantiallycircular second arrangement of greater diameter than that of the firstcircular arrangement, the plurality of sectors being rotatably connectedto a support element and a manual operation, moveably connected to thesupport element, being further provided for moving the sectors from thefirst to the second position and vice versa.
 2. The anchor guide setforth in claim 1, wherein each of the substantially circular sectors hasan arm extending therefrom in a substantially tangential manner andhinged to the support element at its free end, the operation memberacting on the arms.
 3. The anchor guide set forth in claim 1, whereinthe support element is an annular body and the manual operation membercomprises a moveable ring nut rotating coaxially on the annular body andthrust pins extending orthogonally from the moveable ring nut andarranged so as to interfere with the arms during movement of the ringnut, the sliding of the thrust pins along the arms effecting theirangular displacement.
 4. The anchor guide set forth in claim 1, whereinthe arms have a curved profile.
 5. The anchor guide set forth in claim1, wherein the manual operation member further comprises closure pinsextending from the moveable ring nut and also adapted to interfere withthe arms from an opposing portion of the thrust pins.
 6. The anchorguide set forth in claim 1, wherein the arms are housed generallycoplanarly within and relative to the annular body.
 7. The anchor guideset forth in claim 1, wherein the arms are hinged to the support elementthrough pins passing respectively therethrough and engaged withrespective circumferential slots formed along the moveable ring nut,reversible tightening members of the pins abutting the moveable ring. 8.The anchor guide set forth in claim 1, wherein the anchor membercomprises a saw tooth thread formed along an outer surface of thetubular body.
 9. The anchor guide set forth in claim 1, wherein a tubecan be attached within the tubular body in open condition, the tubehaving two elastic disc-shaped membranes extending from its ends andfoldable within it.
 10. The anchor guide set forth in claim 1, whereinthe moveable ring nut includes a fastener for a valve body.
 11. Theanchor guide set forth in claim 10, wherein the valve body comprises afixed support reversibly connected to the moveable ring nut and acontrol ring nut pivotally engaged with the fixed support and maintainedin a desired angular position by flexible arms extending axially fromthe fixed support, the arms having inner radial projections forengagement with axial grooves formed on the edge of the control ringnut.
 12. The anchor guide set forth in claim 1, further comprising avalve having a fixed support reversibly connectable to the manualoperation member, a control ring nut rotatably engaged within the fixedsupport and an elastic membrane obturator having a toroidal shape, atrest, with an “omega” cross section, tightened to the inner walls of thecontrol ring nut and the fixed support, whereby, upon rotating thecontrol ring nut relative to the support, the elastic membrane issubjected to torsion, causing it to close radially like a diaphragm,wherein the control ring nut is maintained in a desired angular positionby flexible arms extending axially from the fixed support, the armshaving inner radial projections for engagement with axial grooves on theedge of the control ring nut.